石墨烯修饰电极同时测定邻苯二酚和对苯二酚

Simultaneous determination of catechol and hydroquinone in graphene modified electrode

制备石墨烯玻碳修饰电极,进而采用循环伏安法、交流阻抗等电化学方法对该电极进行表征,研究该石墨烯修饰电极在邻苯二酚和对苯二酚上的电化学行为.结果表明,在石墨烯修饰电极上邻苯二酚的氧化峰电位和还原峰电位分别是270mV和161mV,对苯二酚氧化峰电位和还原峰电位分别是145mV和64mV,由于邻苯二酚和对苯二酚的氧化峰电位大约相离125mV,还原峰大约相离97mV,因此适合同时检测邻苯二酚和对苯二酚.邻苯二酚和对苯二酚的浓度在5.0×10-6～1.0×10-4 mol/L范围内与峰电流分别呈良好的线性关系;且在8.0×10-5～1.0×10-3 mol/L范围能同时检测邻苯二酚和对苯二酚,邻苯二酚的检测限可达5.0×10-7 mol/L,对苯二酚的检测限可达1.0×10-7 mol/L.该石墨烯修饰电极可作为电化学传感器用于邻苯二酚和对苯二酚的含量同时测定及环境水体中实际样品的分析.

A novel graphene modified glassy carbon electrode was fabricated. The resulting substrates were characterized by Cyclic Voltammetry and EIS in [-Fe （CN）6]3-/4- solution and showed the electrochemical behavior of catechol and hydroquinone on the graphene modified glassy carbon electrode. Experiment result shows that the catechol oxidation peak potential is 270 mV and reduction peak potential is 161 mV, and the hydroquinone oxidation peak potential is 145 mV and reduction peak potential is 64 mV on the graphene modified electrode, respectively. The oxidation peak potential distance is about 125 mV and the reduction peak potential distance is about 97 mV of catechol and hydroquinone which are suited for the simultaneous detection. Catechol and hydroquinone have good electrocatalytic activity on modified electrode and the peak currents of differential pulse voltammetry are liner to the catechol and hydroquinone over the range of 5.0 ×10-8 -1.0× 10-4 mol/L, respectively, and the graphene modified electrode can simultaneously detect catechol and hydroquinone in the rang of 8.0× 10-5-1. 0 × 10-3 mol/L. The catechol detection limit is 5.0 × 10-7 mol/L, the hydroquinone detection limit is 1.0 × 10-7 mol/L. So the graphene modified electrode can be used for analysis the facilitation of actual samples and electrochemical sensors and biosensors.